Mandating that my software stops working unless I pay more for it is a surefire way to make me go somewhere else for software.
I used to buy Adobe Photoshop, and have since moved to Affinity Photo ($50, one-time, does everything I used Photoshop for) since they moved to subscription-only. I outright will never have "Office 365", and strongly recommend to anyone who asks to buy the full retail editions instead. If Microsoft ever switches to 365-only, no big deal, open source software is more than adequate in this area.